gecko-dev/dom/xul/XULDocument.h

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_XULDocument_h
#define mozilla_dom_XULDocument_h

#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsXULPrototypeDocument.h"
#include "nsTArray.h"

#include "mozilla/dom/XMLDocument.h"
#include "mozilla/StyleSheet.h"
#include "nsIContent.h"
#include "nsCOMArray.h"
#include "nsIURI.h"
#include "nsIStreamListener.h"
#include "nsIStreamLoader.h"
#include "nsICSSLoaderObserver.h"

#include "mozilla/Attributes.h"
#include "mozilla/dom/ScriptLoader.h"

#include "js/TracingAPI.h"
#include "js/TypeDecls.h"

class nsPIWindowRoot;
class nsXULPrototypeElement;
#if 0  // XXXbe save me, scc (need NSCAP_FORWARD_DECL(nsXULPrototypeScript))
class nsIObjectInputStream;
class nsIObjectOutputStream;
#else
#  include "nsIObjectInputStream.h"
#  include "nsIObjectOutputStream.h"
#  include "nsXULElement.h"
#endif
#include "nsURIHashKey.h"
#include "nsInterfaceHashtable.h"

/**
 * The XUL document class
 */

// Factory function.
nsresult NS_NewXULDocument(mozilla::dom::Document** result);

namespace mozilla {
namespace dom {

class XULDocument final : public XMLDocument,
                          public nsIStreamLoaderObserver,
                          public nsICSSLoaderObserver,
                          public nsIOffThreadScriptReceiver {
 public:
  XULDocument();

  // nsISupports interface
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_NSISTREAMLOADEROBSERVER

  // Document interface
  virtual void Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup) override;
  virtual void ResetToURI(nsIURI* aURI, nsILoadGroup* aLoadGroup,
                          nsIPrincipal* aPrincipal) override;

  virtual nsresult StartDocumentLoad(const char* aCommand, nsIChannel* channel,
                                     nsILoadGroup* aLoadGroup,
                                     nsISupports* aContainer,
                                     nsIStreamListener** aDocListener,
                                     bool aReset = true,
                                     nsIContentSink* aSink = nullptr) override;

  virtual void SetContentType(const nsAString& aContentType) override;

  virtual void EndLoad() override;

  virtual void InitialDocumentTranslationCompleted() override;

  /**
   * This is invoked whenever the prototype for this document is loaded
   * and should be walked, regardless of whether the XUL cache is
   * disabled, whether the protototype was loaded, whether the
   * prototype was loaded from the cache or created by parsing the
   * actual XUL source, etc.
   *
   * @param aResumeWalk whether this should also call ResumeWalk().
   * Sometimes the caller of OnPrototypeLoadDone resumes the walk itself
   */
  nsresult OnPrototypeLoadDone(bool aResumeWalk);

  // nsINode interface overrides
  virtual nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;

  // nsICSSLoaderObserver
  NS_IMETHOD StyleSheetLoaded(mozilla::StyleSheet* aSheet, bool aWasAlternate,
                              nsresult aStatus) override;

  virtual void EndUpdate() override;

  virtual bool IsDocumentRightToLeft() override;

  /**
   * Reset the document direction so that it is recomputed.
   */
  void ResetDocumentDirection();

  NS_IMETHOD OnScriptCompileComplete(JSScript* aScript,
                                     nsresult aStatus) override;

  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(XULDocument, XMLDocument)

  void TraceProtos(JSTracer* aTrc);

 protected:
  virtual ~XULDocument();

  // Implementation methods
  friend nsresult(::NS_NewXULDocument(Document** aResult));

  nsresult Init(void) override;
  nsresult StartLayout(void);

  nsresult PrepareToLoad(nsISupports* aContainer, const char* aCommand,
                         nsIChannel* aChannel, nsILoadGroup* aLoadGroup,
                         nsIParser** aResult);

  nsresult PrepareToLoadPrototype(nsIURI* aURI, const char* aCommand,
                                  nsIPrincipal* aDocumentPrincipal,
                                  nsIParser** aResult);

  void CloseElement(Element* aElement);

  static void DirectionChanged(const char* aPrefName, XULDocument* aData);

  // pseudo constants
  static int32_t gRefCnt;

  static LazyLogModule gXULLog;

  virtual JSObject* WrapNode(JSContext* aCx,
                             JS::Handle<JSObject*> aGivenProto) override;

  // IMPORTANT: The ownership implicit in the following member
  // variables has been explicitly checked and set using nsCOMPtr
  // for owning pointers and raw COM interface pointers for weak
  // (ie, non owning) references. If you add any members to this
  // class, please make the ownership explicit (pinkerton, scc).
  // NOTE, THIS IS STILL IN PROGRESS, TALK TO PINK OR SCC BEFORE
  // CHANGING

  XULDocument* mNextSrcLoadWaiter;  // [OWNER] but not COMPtr

  bool mIsWritingFastLoad;
  bool mDocumentLoaded;
  /**
   * Since ResumeWalk is interruptible, it's possible that last
   * stylesheet finishes loading while the PD walk is still in
   * progress (waiting for an overlay to finish loading).
   * mStillWalking prevents DoneLoading (and StartLayout) from being
   * called in this situation.
   */
  bool mStillWalking;

  uint32_t mPendingSheets;

  /**
   * Context stack, which maintains the state of the Builder and allows
   * it to be interrupted.
   */
  class ContextStack {
   protected:
    struct Entry {
      nsXULPrototypeElement* mPrototype;
      nsIContent* mElement;
      int32_t mIndex;
      Entry* mNext;
    };

    Entry* mTop;
    int32_t mDepth;

   public:
    ContextStack();
    ~ContextStack();

    int32_t Depth() { return mDepth; }

    nsresult Push(nsXULPrototypeElement* aPrototype, nsIContent* aElement);
    nsresult Pop();
    nsresult Peek(nsXULPrototypeElement** aPrototype, nsIContent** aElement,
                  int32_t* aIndex);

    nsresult SetTopIndex(int32_t aIndex);
  };

  friend class ContextStack;
  ContextStack mContextStack;

  /**
   * Load the transcluded script at the specified URI. If the
   * prototype construction must 'block' until the load has
   * completed, aBlock will be set to true.
   */
  nsresult LoadScript(nsXULPrototypeScript* aScriptProto, bool* aBlock);

  /**
   * Execute the precompiled script object scoped by this XUL document's
   * containing window object.
   */
  nsresult ExecuteScript(nsXULPrototypeScript* aScript);

  /**
   * Create a delegate content model element from a prototype.
   * Note that the resulting content node is not bound to any tree
   */
  nsresult CreateElementFromPrototype(nsXULPrototypeElement* aPrototype,
                                      Element** aResult, bool aIsRoot);

  /**
   * Add attributes from the prototype to the element.
   */
  nsresult AddAttributes(nsXULPrototypeElement* aPrototype, Element* aElement);

  /**
   * The prototype-script of the current transcluded script that is being
   * loaded.  For document.write('<script src="nestedwrite.js"><\/script>')
   * to work, these need to be in a stack element type, and we need to hold
   * the top of stack here.
   */
  nsXULPrototypeScript* mCurrentScriptProto;

  /**
   * Whether the current transcluded script is being compiled off thread.
   * The load event is blocked while this is in progress.
   */
  bool mOffThreadCompiling;

  /**
   * If the current transcluded script is being compiled off thread, the
   * source for that script.
   */
  char16_t* mOffThreadCompileStringBuf;
  size_t mOffThreadCompileStringLength;

 protected:
  /**
   * The current prototype that we are walking to construct the
   * content model.
   */
  RefPtr<nsXULPrototypeDocument> mCurrentPrototype;

  /**
   * Owning references to all of the prototype documents that were
   * used to construct this document.
   */
  nsTArray<RefPtr<nsXULPrototypeDocument> > mPrototypes;

  /**
   * Prepare to walk the current prototype.
   */
  nsresult PrepareToWalk();

  /**
   * Creates a processing instruction based on aProtoPI and inserts
   * it to the DOM.
   */
  nsresult CreateAndInsertPI(const nsXULPrototypePI* aProtoPI, nsINode* aParent,
                             nsINode* aBeforeThis);

  /**
   * Inserts the passed <?xml-stylesheet ?> PI at the specified
   * index. Loads and applies the associated stylesheet
   * asynchronously.
   * The prototype document walk can happen before the stylesheets
   * are loaded, but the final steps in the load process (see
   * DoneWalking()) are not run before all the stylesheets are done
   * loading.
   */
  nsresult InsertXMLStylesheetPI(const nsXULPrototypePI* aProtoPI,
                                 nsINode* aParent, nsINode* aBeforeThis,
                                 nsIContent* aPINode);

  /**
   * Resume (or initiate) an interrupted (or newly prepared)
   * prototype walk.
   */
  nsresult ResumeWalk();

  /**
   * Called at the end of ResumeWalk(), from StyleSheetLoaded(),
   * and from DocumentL10n.
   * If walking, stylesheets and l10n are not blocking, it
   * will trigger `DoneWalking()`.
   */
  nsresult MaybeDoneWalking();

  /**
   * Called from `MaybeDoneWalking()`.
   * Expects that both the prototype document walk is complete and
   * all referenced stylesheets finished loading.
   */
  nsresult DoneWalking();

  class CachedChromeStreamListener : public nsIStreamListener {
   protected:
    RefPtr<XULDocument> mDocument;
    bool mProtoLoaded;

    virtual ~CachedChromeStreamListener();

   public:
    CachedChromeStreamListener(XULDocument* aDocument, bool aProtoLoaded);

    NS_DECL_ISUPPORTS
    NS_DECL_NSIREQUESTOBSERVER
    NS_DECL_NSISTREAMLISTENER
  };

  friend class CachedChromeStreamListener;

  bool mInitialLayoutComplete;

 private:
  // helpers
};

inline XULDocument* Document::AsXULDocument() {
  MOZ_ASSERT(IsXULDocument());
  return static_cast<mozilla::dom::XULDocument*>(this);
}

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_XULDocument_h